From bluestem@webserf.net Thu May 20 09:24:17 1999
Date: Thu, 20 May 1999 10:07:18 +0100
From: Bluestem Associates
To: "sanet-mg@ces.ncsu.edu"
Subject: Nitrogen in organic agriculture
I should think if any group would understand that use patterns and
results would be all over the map, it would be *this* one. That said,
a few observations.
Many (perhaps most) of the organic farms that I inspect do *not*
capture enough nitrogen to maintain a productive system over the long
term. In that respect Avery and some of the other naysayers have a
valid *empirical* point. These farms, however, are almost always short
of nitrogen owing to poor nitrogen management (insufficient N fixation,
manure management problems, etc.).
It is entirely possible for a well-managed organic farm to capture all
the nitrogen needed for "high-yield" production. In fact, it is not at
all uncommon for an organic system to become too *rich* in nitrogen one
or two rotation cycles after the transition, at which point the grower
shifts to mixed hay (rather than straight legumes) and things settle
down.
Virtually all farmers (organic and otherwise) neglect the valuable role
played by molybdenum in improving the efficiency of nitrogen capture.
With well-considered additions of molybdenum, it is quite possible to
capture more solar energy (through increased yields) than can be
released from an equal weight of uranium via nuclear power. A few grams
per hectare is usually all that it takes, added with inoculant at
seeding. This because the nitrogenase component of the rhizobial
nitrogen fixation reaction is dependent on an Fe-Mo protein, with moly
being the limiting factor.
Editorial comment about Chilean nitrate --- if organic is to allow any
soluble nitrogen at all, it should be in the form of ammonium sulfate,
not as a nitrate. Every other nutrient sulfate is already permitted,
and AS is much better for soil microbes than the nitrates. Also, any
idea that an organic inspector can determine the difference between
10-20 kg/ha nitrate and 50-60 kg/ha or even more (split apps) is ...
pure fantasy.
I have to chuckle when the naysayers criticise organic production as
"inefficient" when their Farm Bureau buddies routinely knife in 400
units of anhydrous per acre every autumn and then have to come back
over their corn with liquid 28 the following season just to make sure
they have "enough."
Conventional American agriculture is "efficient" (I suppose) in the
same way as the American consumer economy. You can jump into a 2-ton
SUV and drive it three blocks to pick up a 2-ounce packet of razor
blades, and marvel at the "efficiency" of it all--- and look down one's
nose at the scruffy unshaven neighbours -- but it is tragically
laughable to conclude from that situation that walking and bicycles are
inadequate.
Bart Hall
Lawrence, Kansas
To Unsubscribe: Email majordomo@ces.ncsu.edu with the command
"unsubscribe sanet-mg". If you receive the digest format, use the command
"unsubscribe sanet-mg-digest".
To Subscribe to Digest: Email majordomo@ces.ncsu.edu with the command
"subscribe sanet-mg-digest".
All messages to sanet-mg are archived at:
http://www.sare.org/san/htdocs/hypermail